SpringBoot3.0.0-SNAPSHOT与swagger3不兼容问题解决_swagger 3.0.0不支持spring3.0.0

        最近将SpringBoot升级到了SpringBoot3.0.0-SNAPSHOT版本，我项目里面集成的swagger是springfox-swagger2的3.0.0版本。maven clean和install都没问题。可是运行项目时程序报错。报错如下：

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2022-07-25T17:33:19.262+08:00 ERROR 9612 --- [           main] o.s.boot.SpringApplication               : Application run failed
 
org.springframework.context.ApplicationContextException: Failed to start bean 'documentationPluginsBootstrapper'
	at org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:181) ~[spring-context-6.0.0-20220722.142958-638.jar:6.0.0-SNAPSHOT]
	at org.springframework.context.support.DefaultLifecycleProcessor$LifecycleGroup.start(DefaultLifecycleProcessor.java:356) ~[spring-context-6.0.0-20220722.142958-638.jar:6.0.0-SNAPSHOT]
	at java.base/java.lang.Iterable.forEach(Iterable.java:75) ~[na:na]
	at org.springframework.context.support.DefaultLifecycleProcessor.startBeans(DefaultLifecycleProcessor.java:155) ~[spring-context-6.0.0-20220722.142958-638.jar:6.0.0-SNAPSHOT]
	at org.springframework.context.support.DefaultLifecycleProcessor.onRefresh(DefaultLifecycleProcessor.java:123) ~[spring-context-6.0.0-20220722.142958-638.jar:6.0.0-SNAPSHOT]
	at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:943) ~[spring-context-6.0.0-20220722.142958-638.jar:6.0.0-SNAPSHOT]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:595) ~[spring-context-6.0.0-20220722.142958-638.jar:6.0.0-SNAPSHOT]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:146) ~[spring-boot-3.0.0-20220725.081705-662.jar:3.0.0-SNAPSHOT]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:735) ~[spring-boot-3.0.0-20220725.081705-662.jar:3.0.0-SNAPSHOT]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:434) ~[spring-boot-3.0.0-20220725.081705-662.jar:3.0.0-SNAPSHOT]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) ~[spring-boot-3.0.0-20220725.081705-662.jar:3.0.0-SNAPSHOT]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1307) ~[spring-boot-3.0.0-20220725.081705-662.jar:3.0.0-SNAPSHOT]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1296) ~[spring-boot-3.0.0-20220725.081705-662.jar:3.0.0-SNAPSHOT]
	at com.lvxiaosha.Application.main(Application.java:22) ~[classes/:na]
Caused by: java.lang.NullPointerException: Cannot invoke "org.springframework.web.servlet.mvc.condition.PatternsRequestCondition.getPatterns()" because "this.condition" is null
	at springfox.documentation.spring.web.WebMvcPatternsRequestConditionWrapper.getPatterns(WebMvcPatternsRequestConditionWrapper.java:56) ~[springfox-spring-webmvc-3.0.0.jar:3.0.0]
	at springfox.documentation.RequestHandler.sortedPaths(RequestHandler.java:113) ~[springfox-core-3.0.0.jar:3.0.0]
	at springfox.documentation.spi.service.contexts.Orderings.lambda$byPatternsCondition$3(Orderings.java:89) ~[springfox-spi-3.0.0.jar:3.0.0]
	at java.base/java.util.Comparator.lambda$comparing$77a9974f$1(Comparator.java:473) ~[na:na]
	at java.base/java.util.TimSort.countRunAndMakeAscending(TimSort.java:355) ~[na:na]
	at java.base/java.util.TimSort.sort(TimSort.java:234) ~[na:na]
	at java.base/java.util.Arrays.sort(Arrays.java:1307) ~[na:na]
	at java.base/java.util.ArrayList.sort(ArrayList.java:1721) ~[na:na]
	at java.base/java.util.stream.SortedOps$RefSortingSink.end(SortedOps.java:392) ~[na:na]
	at java.base/java.util.stream.Sink$ChainedReference.end(Sink.java:258) ~[na:na]
	at java.base/java.util.stream.Sink$ChainedReference.end(Sink.java:258) ~[na:na]
	at java.base/java.util.stream.Sink$ChainedReference.end(Sink.java:258) ~[na:na]
	at java.base/java.util.stream.Sink$ChainedReference.end(Sink.java:258) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:510) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499) ~[na:na]
	at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:921) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:682) ~[na:na]
	at springfox.documentation.spring.web.plugins.WebMvcRequestHandlerProvider.requestHandlers(WebMvcRequestHandlerProvider.java:81) ~[springfox-spring-webmvc-3.0.0.jar:3.0.0]
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197) ~[na:na]
	at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1625) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499) ~[na:na]
	at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:921) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:682) ~[na:na]
	at springfox.documentation.spring.web.plugins.AbstractDocumentationPluginsBootstrapper.withDefaults(AbstractDocumentationPluginsBootstrapper.java:107) ~[springfox-spring-web-3.0.0.jar:3.0.0]
	at springfox.documentation.spring.web.plugins.AbstractDocumentationPluginsBootstrapper.buildContext(AbstractDocumentationPluginsBootstrapper.java:91) ~[springfox-spring-web-3.0.0.jar:3.0.0]
	at springfox.documentation.spring.web.plugins.AbstractDocumentationPluginsBootstrapper.bootstrapDocumentationPlugins(AbstractDocumentationPluginsBootstrapper.java:82) ~[springfox-spring-web-3.0.0.jar:3.0.0]
	at springfox.documentation.spring.web.plugins.DocumentationPluginsBootstrapper.start(DocumentationPluginsBootstrapper.java:100) ~[springfox-spring-web-3.0.0.jar:3.0.0]
	at org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:178) ~[spring-context-6.0.0-20220722.142958-638.jar:6.0.0-SNAPSHOT]
	... 13 common frames omitted

        新增Swagger2配置类，内容如下：

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.util.ReflectionUtils;
import org.springframework.web.servlet.mvc.method.RequestMappingInfoHandlerMapping;
import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.service.ApiInfo;
import springfox.documentation.service.Contact;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.spring.web.plugins.WebFluxRequestHandlerProvider;
import springfox.documentation.spring.web.plugins.WebMvcRequestHandlerProvider;
import springfox.documentation.swagger2.annotations.EnableSwagger2;
 
import java.lang.reflect.Field;
import java.util.List;
import java.util.stream.Collectors;
 
@Configuration
@EnableSwagger2
public class Swagger2 {
 
//    http://localhost:8088/swagger-ui.html     原路径
//    http://localhost:8088/doc.html     原路径
 
    // 配置swagger2核心配置 docket
    @Bean
    public Docket createRestApi() {
        return new Docket(DocumentationType.SWAGGER_2)  // 指定api类型为swagger2
                    .apiInfo(apiInfo())                 // 用于定义api文档汇总信息
                    .select()
                    .apis(RequestHandlerSelectors
                            .basePackage("com.lvxiaosha.controller"))   // 指定controller包
                    .paths(PathSelectors.any())         // 所有controller
                    .build();
    }
 
    private ApiInfo apiInfo() {
        return new ApiInfoBuilder()
                .title("吕小傻学习项目接口api")        // 文档页标题
                .contact(new Contact("lvxiaosha",
                        "https://www.lvxiaosha.com",
                        "abc@lvxiaosha.com"))        // 联系人信息
                .description("吕小傻学习项目接口api文档")  // 详细信息
                .version("1.0.0")   // 文档版本号
                .termsOfServiceUrl("https://www.lvxiaosha.com") // 网站地址
                .build();
    }
 
    /**
     * 增加如下配置可解决Spring Boot 6.x 与Swagger 3.0.0 不兼容问题
     **/
    @Bean
    public static BeanPostProcessor springfoxHandlerProviderBeanPostProcessor() {
        return new BeanPostProcessor() {
 
            @Override
            public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
                if (bean instanceof WebMvcRequestHandlerProvider || bean instanceof WebFluxRequestHandlerProvider) {
                    customizeSpringfoxHandlerMappings(getHandlerMappings(bean));
                }
                return bean;
            }
 
            private <T extends RequestMappingInfoHandlerMapping> void customizeSpringfoxHandlerMappings(List<T> mappings) {
                List<T> copy = mappings.stream()
                        .filter(mapping -> mapping.getPatternParser() == null)
                        .collect(Collectors.toList());
                mappings.clear();
                mappings.addAll(copy);
            }
 
            @SuppressWarnings("unchecked")
            private List<RequestMappingInfoHandlerMapping> getHandlerMappings(Object bean) {
                try {
                    Field field = ReflectionUtils.findField(bean.getClass(), "handlerMappings");
                    field.setAccessible(true);
                    return (List<RequestMappingInfoHandlerMapping>) field.get(bean);
                } catch (IllegalArgumentException | IllegalAccessException e) {
                    throw new IllegalStateException(e);
                }
            }
        };
    }
 
}

        再次启动项目，报错解决。